A through via structure is configured as a conductive interconnection to interconnect two conductive structures such as conductive wirings or electrodes disposed on two opposite sides of the dielectric layer or the insulation layer. For high-density package application, the dimension of through via structure has shrank to micron or sub-micron level, and the aspect ratio of the through via structure is accordingly increased. For a via hole with high aspect ratio, however, void or seam tends to occur when filling a conductive layer into the via hole. In addition, corrosion issue due to galvanic effect tends to occur.